This invention relates to an aircraft, in particular to an unmanned aerial vehicle (UAV).
UAVs are employed in a variety of roles, such as reconnaissance/surveillance or for delivering a payload in the form of a munition or goods such as stores. Traditionally, UAVs are specifically designed for the roles they are intended for, so that a surveillance UAV is typically designed so as to have a high endurance (and so usually has a relatively low flight speed), whereas a xe2x80x9cstrikexe2x80x9d UAV (for delivering a warhead) will usually be designed for relatively high speed flight, so as to minimise vulnerability of the UAV to anti-aircraft measures. This diversity of UAV design tends to inhibit the full exploitation of UAVs.
It is an object of the present invention to provide an aircraft which is sufficiently versatile to encourage and facilitate wider use of UAVs.
According, the present invention provides an aircraft comprising at least one pair of wings comprising means for propelling the aircraft in flight, means for controlling the propulsion means and for controlling the aircraft in flight, and a fuselage, wherein each wing is detachably connected to the fuselage, the control means are located within the wings and the fuselage comprises means for connecting the control means and the propulsion means in the associated wings of each pair of wings thereby to enable controlled flight of the aircraft.
With such an arrangement, a UAV can be configured and used with one fuselage in one role, and rapidly re-configured using a different fuselage and the same set of wings for a second rolexe2x80x94the UAV could deliver a payload of stores and be reconfigured (by connecting the wings to another fuselage) as a xe2x80x9ccruisexe2x80x9d-type missile, for example (reconfiguration would be carried out on the ground, as opposed to in flight). In addition, the module arrangement of the wings and fuselage enables quicker and simpler repair and maintenance; in the event one propulsion means (engine) is faulty, or one wing is damaged, the aircraft can be made airworthy rapidly and easily merely by replacing the whole wing.
Preferably the wings contain the fuel tanks. This means that the fuselage can be made as elementary as possible; apart from the connecting means, or xe2x80x9cbusxe2x80x9d, which allows the intercommunication and control of each pair of wings and engines necessary for unmanned flight, the fuselage is little more than an aerodynamically-shaped container, which can be adapted according to the role of the UAV and the payload to be carried.
The propulsion means may be rotatable about an axis perpendicular to the direction of forward flight of the aircraft, and/or means may be provided selectively to divert efflux from the propulsion means, thereby selectively to provide propulsion of for forward flight or for vertical take-off and/or landing of the aircraft.
These arrangements, which ideally would utilise technology already in use in manned VTOL/VSTOL (vertical take-off and landing, vertical/short take off and landing) aircraft, allow the UAV to be used in a VTOL or VSTOL role with the consequent advantages thereof (no need for a prepared runway, therefore allowing the UAV to operate from or to a remote site, behind enemy lines, onboard a ship and so on).
It has already been explained how the fuselage may be simple in design; where a role requires a substantial payload to be carried, two or more fuselages may be connected together, between a pair of wings thus increasing the maximum payload. Connection of the fuselages and of the pair of wings would be by way of the means provided on the fuselage for connection to the wings and the aircraft xe2x80x9cbusxe2x80x9d respectively.
However the aircraft is configured it will also preferably comprise other conventional aircraft features, such as a tail fin, movable control surfaces (which may be integral with the wings) and an undercarriage. Because an undercarriage is only required where the UAV is not used in a sacrificial role (i.e. as a missile), in the interest of maximising versatility it would be preferable for the undercarriage to be integral with the fuselage, so that only a fuselage adapted for a repeated use role need be provided with an undercarriage, whereas for a missile role there need be no undercarriage and the fuselage could be specially designed for its xe2x80x9cstrikexe2x80x9d role.
The invention will now be described by way of example and with reference to the accompanying drawings, in which:
FIG. 1 is a schematic illustration of an unmanned aircraft in accordance with the invention;
FIGS. 2A and B are schematic front, plan and side views of a wing forming part of an aircraft in accordance with the invention and having a rotationally mounted engine on the outboard wing tip, arranged for forward flight and for vertical flight respectively;
FIG. 3 comprises schematic front, plan and side views of a wing similar to that of FIGS. 2A and B but having a fixed engine on the outboard wingtip but provided with vectorable nozzles, for selective horizontal or vertical flight;
FIG. 4 is a schematic view of a fuselage for use with the wings of FIGS. 2 and 3, and
FIG. 5 is a schematic view of a fuselage formed by connecting together two of the fuselages of FIG. 4.